Personal GPS locators are meant to provide peace of mind. Anyone—a child, an adult with dementia, or even a pet—who carries or wears one of these GPS devices should be easily and quickly findable. But our tests found that's not always the case.
Our lab tested the Amber Alert GPS, $130 plus $15 per month; the Filip, worn on the wrist, $200 plus $10 per month, and the the PocketFinder Personal GPS Locator (which can be used on pets as well as people), $130 plus $13 per month.
The devices use GPS or a combination of GPS, Wi-Fi, and cell-phone signals to determine their location. They then communicate it through the AT&T cellular network (subscription required) to either a Web page or a smart-phone app that's monitored by the parent or guardian.
The Amber Alert and Filip are also limited cell phones: They don't let the wearer dial a number directly, but the wearer can be contacted or issue an SOS. And all three let you set zones—so, for instance, a parent can receive an alert when a child has strayed out of a designated safe area or into a problem area.
All three devices work as claimed—sometimes. And that's a problem.
The devices determine and communicate their location only intermittently: the PocketFinder every 2 minutes, Amber Alert every 5 minutes, and Filip every 15 minutes. As a result, the reported location is often old. Even when the devices are pinged with a command to report their location, that info may take a minute to appear.
The reported location will also be old if the device can't read the GPS signal, which often happens indoors. And none of the apps proactively communicate to the monitoring person that the device has lost the GPS signal. The Amber Alert, for instance, informed our tester that it was a half-mile from him, as it sat on his desk all day.
Only one, the PocketFinder, had a setting that appeared to provide real-time continuous location information. Unfortunately, the continuously updated location was that of the smart phone running the app, and not that of the device itself, which was shown in a static position though it was actually moving.
Given the concern about their ability to provide up-to-the-minute location information, the peace of mind provided by these devices can be limited. Until they can provide nearly continuous tracking information—at least every minute, if not more often—they aren't very useful.